Reclamation of alloy



Sept. 6, 1966 E. E. DICKEY 3,271,131

RECLAMATION OF ALLOY Filed Aug. 19, 1965 ALUMINUM ALLOY Al Zn OTHER METALS ZINC VAPOR HEAT ABOVE BOILING ll POINT OF ZINC COOLING PURIFIED ALLOY Al OTHER METALS INVENTOR. EDWARD E. DIG/(E Y ATTORNEY United States Patent 3,271,131 RECLAMATHON 0F ALLOY Edward E. Dickey, RED. 1, Millersport, Ohio Filed Aug. 19, 1963, Ser. No. 305,917 12 Claims. (Cl. 7563) The invention disclosed and claimed in this application relates to a process of purifying alloys. It is illustrated by various embodiments consisting of processes of purifying various aluminum alloys from zinc which is considered a contaminant in these alloys.

One of the objects of my invention as described herein is the purification of alloys by the elimination of zinc.

A further more specific object of the invention is the provision of processes whereby alloys containing a major portion of aluminum and smaller amounts of some of such metals as beryllium, bismuth, boron, chromium, magn'esium and titanium, copper, lead, iron, manganese, nickel, silicon, and tin, and also containing at least a small amount of Zinc may be purified of such zinc which can be considered as a contaminant.

A further very specific object of the invention is a provision of a process wherein a metal alloy containing a major portion of aluminum and smaller portions of copper, iron, silicon, manganese and zinc may be purified by the elimination of Zinc.

A further very specific object of the inventionis the provision of a process wherein a metal alloy containing a major portion of aluminum and smaller portions of copper, manganese, zinc and chromium may be purified by the elimination of zinc.

Further specific objects of the invention are the provision of processes wherein metal alloys containing in each case a major portion of aluminum and a minor portion of zinc and containing also minor proportions of other metals such as (for example only), the combinations set out below may be purified by the removal of substantially all of the Zinc.

(a) alloys containing aluminum,

copper (b) alloys containing aluminum,

copper and magnesium (c) alloys containing aluminum,

copper, iron and silicon (d) alloys containing aluminum, zinc, and in addition copper, iron, silicon and manganese.

A further object of the invention is the modification of alloys of all types including those referred to in the preceding objects by the elimination of all but an inconsequential portion of the zinc in the alloy so that the alloy is for all practical purposes pure and so that the amount of zinc retained in such alloys is substantially not detrimental thereto.

A further object of the invention is the improvement of alloys by the reduction of the amount of Zinc impurities contained therein utilizing the equipment presently used in Working with such alloys.

Other objects, features and advantages of my invention should be apparent from a further consideration of this specification and the claims following and the attached drawings.

In the drawings:

The figure is a flow sheet illustrating a process comprising an embodiment of my invention.

Referring to the drawing for a more detailed d'escrip tion of the invention, it may be pointed out that in the formation of many aluminum alloys, zinc is considered a contaminant. In such cases Where the alloy is found to contain a substantial proportion of zinc, the entire melt has to be sold as scrap at a price of perhaps 12 a pound, whereas if the Zinc could be eliminated, or substantially zinc, and in addition zinc, and in addition zinc, and in addition Patented Sept. 6, 1966 "ice reduced, the alloy will readily be sold at at least 22 a pound.

I have discovered that many alloys can be purified by heating the alloy to a point above the melting point of the alloy, and above the boiling point of zinc, but below the boiling point of the other desired constituents of the alloy. These alloys melt at about 1300" F. At about 1650 F. the Zinc boils olf. Thus, the zinc impurity may be eliminated. This is true, because fortunately the boiling point of zinc is relatively low and is lower than the boiling point of aluminum and of the other constituents of most aluminum alloys.

I preferto use temperatures of 1800" F. or less because presently used furnaces and temperature recording devices can stand such temperature but cannot stand temperatures appreciably higher.

Following are examples which are illustrative of my process.

Example I An alloy was prepared consisting mainly of aluminum, zinc, and copper. On analysis it was found to contain copper 4.6%, zinc 4.13%, and the remainder essentially aluminum. On heating to 1700 F. (927 C.), alloy melts including the dissolved copper and the zinc boils oif to leave an essentially aluminum-copper alloy substantially free of zinc.

In heating the alloy to this temperature a small part of the aluminum fumes are carried off into the atmosphere and most of the zinc goes off as fumes with the aluminum fumes.

Example II An alloy was prepared consisting mainly of aluminum, zinc, copper, manganese, silicon, and iron. On analysis it was found to contain copper 4.5%, manganese 0.7%,

silicon 1.0%, iron 0.4%, zinc 5.12%. and the remainder essentially aluminum. On heating to 1700 F., the alloy melts including all of the constituents dissolved in the alloy and substantially all of the Zinc boils oif to leave an aluminum-copper-manganese-silicon-iron alloy substantially free of zinc having less than 0.20% of zinc.

Example III An alloy Was prepared consisting mainly of aluminum, Zinc, copper, and magnesium. On analysis it was found to contain copper 4.3%, magnesium 1.5%, zinc 6.1%, and the remainder essentially aluminum. On heating to 1700 F., the alloy including all of the constituents melts and the zinc boils off'to leave an aluminum-coppermagnesium alloy substantially free of zinc, having less than 0.25% of zinc.

Example IV An alloy was prepared consisting mainly of aluminum, zinc, copper and iron. On analysis it was found to contain copper 5.0%, iron 0.4%, zinc 5.1%, and the remainder essentially aluminum. On heating to 1700 F. the alloy including all of the constituents melts and the zinc boils off to leave an aluminum-copper-iron alloy substantially free of zinc.

Example V An alloy was prepared consisting mainly of aluminum, Zinc, iron, and silicon. On analysis it was found to contain iron 0.6%, silicon 0.04%, zinc 4.03% and the remainder essentially aluminum. On heating to 1700 F., the alloy including all of the constituents melts and the Zinc boils off to leave an essentially aluminum-iron-silicon alloy substantially free of zinc.

Example VI An alloy was prepared consisting mainly of aluminum, zinc, and manganese. On analysis it was found to contain manganese 1.4%, zinc 4.1% and the remainder essentially aluminum. On heating to 1700" F. the alloy including all of the constituents melts and the zinc boils off to leave an aluminum-manganese alloy substantially free of zinc.

Example VII An alloy was prepared consisting mainly of aluminum, Zinc, and magnesium. On analysis it was found to contain magnesium 5.2%, zinc 5.0% and the remainder essentially aluminum. On heating to 1600 F. the alloy including all of the constituents melts and the zinc boils off to leave an aluminum-magnesium alloy substantially free of zinc.

Example VIII An alloy was prepared consisting mainly of aluminum, zinc, and silicon. On analysis it was found to contain silicon 12.7%, zinc 4.25 and the remainder essentially aluminum. On heating to 1700 F. the alloy including all of the constituents melts and the zinc boils off to leave an aluminum-silicon alloy substantially free of Zinc.

Example IX An alloy was prepared consisting mainly of aluminum, zinc, iron, lead, tin, and copper. On analysis it was found to contain copper 5.7%, zinc 6.08%, iron 0.04%, lead 0.5%, tin 0.05% and the remainder essentially aluminum. On heating to 1700 F., the alloy including all of the constituents melts and the zinc 'boils off to leave an essentially aluminum-copper-iron-lead-tin alloy substantially free of zinc. I

Example X Example XI An alloy was prepared consisting mainly of aluminum, zinc, copper, and manganese. On analysis it was found to contain copper 0.2%, manganese 1.4%, zinc 5.1%, and the remainder essentially aluminum. On heating to 1700 F., the alloy including all of the constituents melts and the zinc boils off to leave an aluminum-coppermanganese alloy substantially free of zinc.

Example XII An alloy was prepared consisting mainly of aluminum, zinc, copper, bismuth and lead. On analysis it was found to contain copper 5.7%, bismuth 0.5%, lead 0.5%, and zinc 6.1%, and the remainder essentially aluminum. On heating to 1700 F. the alloy including all of the constituents melts and the zinc boils off to leave an aluminumcopper-bismuth-lead alloy substantially free of zinc.

Example XIII An alloy was prepared consisting mainly of aluminum, zinc, silicon, and copper. On analysis it was found to contain copper 1.2%, silicon 1,1%, and zinc 4.5%, and the remainder essentially aluminum. On heating to 1700 F., the alloy including all of the constituents melts and the zinc boils off to leave an essentially aluminumcopper-silicon alloy substantially free of Zinc.

Example XIV An alloy was prepared consisting mainly of aluminum, zinc, copper, silicon, and iron. On analysis it was found to contain copper 1.7%, silicon 0.25%, iron 0.9%, zinc 4.25%, and the remainder essentially aluminum. On heating to 1700" F. the alloy including all of the con- I}, stituents melts and the zinc boils off to leave an aluminumcopper-silicon-iron alloy substantially free of Zinc.

Example XV Example XVI An alloy was prepared consisting mainly of aluminum, zinc, silicon and iron. On analysis it was found to contain silicon 0.04%, iron 0.15%, zinc 4.03% and the remainder essentially aluminum. On heating to 1700 F.,

the alloy includingall of the constituents melts and the zinc boils ofi to leave an aluminum-silicon-iron alloy substantially free of zinc.

It is to be understood that the above described embodiments of my invention are for the purpose of illustration only and various changes may be made therein without departing from the spirit and scope of the invention.

I claim:

1. A method of purifying an aluminum alloy of zinc impurities where the alloy consists of at least of aluminum, from 4 to 6.5% of zinc, together with from 0.64 to 13% of at least one metal selected from the group consisting of beryllium, boron, bismuth, chromium, copper, iron, lead, magnesium, manganese, nickel, silicon, tin, and titanium comprising heating the alloy to a temperature in the range of from 1665 F. to 1800 F. at a temperature of about 1700 P. which is below the boiling point of all of the other constituents of the alloy excepting zinc; allowing zinc to evaporate from the liquid alloy; and cooling the remaining liquid to secure an aluminum alloy, substantially'free of zinc.

2. A process of purifying an aluminum alloy from zinc impurities according to the method of claim 1, where the alloy consists of aluminum, copper, and zinc,

where the aluminum alloy secured is an alloy consisting essentially of aluminum, and copper.

3. A process of purifying an aluminum alloy from zinc impurities, according to the method of claim 1, where the alloy consists of aluminum, copper, iron, and zinc,

and where the aluminum alloy secured is an alloy consisting essentially of aluminum, copper, and iron.

4. A process of purifying an aluminum alloy from zinc impurities according to the method of claim 1 where the impure alloy consists of aluminum, iron, silicon, and zinc, and where the alloy secured is an alloy consisting essentially of aluminum, iron, and silicon.

5. A process of purifying an aluminum alloy from zinc impurities, according to the method of claim 1 where the alloy consists of aluminum, manganese, and zinc, and where the alloy secured is an alloy consisting essentially of aluminum and manganese.

6. A process of purifying an aluminum alloy from zinc impurities, according to the method of claim 1 where the alloy consists of aluminum, silicon, and zinc, and where the alloy secured is an alloy consisting essentially of aluminum and silicon.

7. A process of purifying an aluminum alloy from zinc impurities according to the method of claim 1 where the impure alloy consists of aluminum, copper, lead, tin, and Zinc, and where the alloy secured is an alloy consisting essentially of aluminum, copper, lead, and tin.

8. A process of purifying an aluminum alloy from zinc impurities, according to the method of claim 1 where the alloy consists of aluminum, copper, manganese, silicon, tin and zinc, and where the alloy secured is an alloy consisting substantially of aluminum, copper, tin, manga nese and silicon.

9. A process of purifying an aluminum alloy from zinc impurities according to the method of claim 1 Where the impure alloy consists of aluminum, copper, manganese and zinc, and where the alloy secured is an alloy consisting of essentially aluminum, copper, and manganese.

10. A process of purifying an aluminum alloy from zinc impurities according to the method of claim 1 where the impure alloy consists of aluminum, copper, and silicon, and zinc, and where the alloy secured is an alloy consisting of essentially aluminum, copper, and silicon.

11. A process of purifying an aluminum alloy from zinc impurities, according to the method of claim 1 where the alloy consists of aluminum, copper, iron, silicon and zinc, and Where the alloy secured is an alloy consisting of essentially aluminum, iron, silicon, and copper.

12. A process of purifying an aluminum alloy from zinc impurities according to the method of claim 1 where the impure alloy consists of aluminum, copper, silicon, manganese, and zinc, and Where the alloy secured is an alloy consisting of essentially aluminum, copper, silicon and manganese.

References Cited by the Examiner UNITED STATES PATENTS 3/ 19-35 Holstein 7563 7/1950 Loevenstein 7568 OTHER REFERENCES Handbook of Chemistry and Physics, 41st Ed., 1959,

DAVID L. RECK, Primary Examiner.

BENJAMIN HENKIN, HYLAND B IZOT, Examiners.

20 H. W. CUM MINGS, H. W. TARRING,

Assistant Examiners. 

1. A METHOD OF PURIFYING AN ALUMINUM ALLOY OF ZINC IMPURITIES WHERE THE ALLOY CONSISTS OF AT LEAST 80% IF ALUMINUM, FROM 4 TO 6.5% OF ZINC, TOGETHER WITH FROM 0.64 TO 13% OF AT LEST ONE METAL SELECTED FROM THE GROUP CONSISTING OF BERYLLIUM, BORON, BISMUTH, CHROMIUM, COPPER, IRON, LEAD, MAGNESIUM, MANGANESE, NICKEL, SILICON, TIN, AND TITANIUM COMPRISING HEATING THE ALLOY TO A TEMPERATURE IN THE RANGE OF FROM 1665*F. TO 1800*F. AT A TEMPERATURE OF ABOUT 1700* F. WHICH IS BELOW THE BOILING POINT OF ALL OF THE OTHER CONSTITUENTS OF THE ALLOY EXCEPTING ZINC; ALLOWING ZINC TO EVAPORATE FROM THELIQUID ALLOY; AND COOLING THE REMAINING LIQUID TO SECURE AN ALUMINUM ALLOY, SUBSTANTIALLY FREE OF ZINC. 